The purpose is to investigate the effect of calcium ion on oxidative metabolism and lipid synthesis by the lung. We propose that intracellular calcium ion determines the rate of alpha-glycerophosphate dehydrogenase activity which in turn determines intracellular concentration of alpha-glycerophosphate and dihydroxyacetone phosphate. We are investigating the role of alpha GP and DHAP in lipid synthesis by lung microsomes and lung mitochondrial preparations. We are also using the isolated perfused lung to study pathways of glucose and palmitate oxidation and de novo synthesis of phospholipids. We are also investigating intracellular redox state through measurement of redox couples of the freeze-clamped perfused lung. These studies will be performed with and without addition of calcium ion to the perfusate in order to manipulate intracellular calcium ion concentration.